42 research outputs found

    Effectiveness of Azadirachta indica A. Juss (Neem) Seed Oil in Controlling Wood Termite

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    The protection of wood against biodeteriorating agents like termite during processing or in service has call for serious possible approach using new safer, environmental friendly preservatives hence this study therefore evaluated Azadirachta indica seed oil against termite attack on Gmelina arborea and Triplochiton scleroxylon wood. The seed oil was obtained using a soxhlet apparatus and N-hexane as the solvent. The wood was dimensioned into 20x20x20 mm and the seed oil was applied by brushing, dipping and soaking and exposed to termitarium while the absorption rate and weight loss to termite attack were determined. Data collected was analyzed using simple statistics and analysis of variance at \u3b10.05. The antimicrobial properties of the need seed oil are due to the availability of phytochemicals which promote antimicrobial activity. The maximum wood protection against termite of all the methods of application was obtained from soaking. The absorption and weight loss ranged from 11.20 - 43.88 % and 56.50 -61.58 % for G. arborea and T. scleroxylon respectively. However, all the application methods used for the wood treatment proved to be effective over the untreated wood

    Histone Variants and Their Post-Translational Modifications in Primary Human Fat Cells

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    Epigenetic changes related to human disease cannot be fully addressed by studies of cells from cultures or from other mammals. We isolated human fat cells from subcutaneous abdominal fat tissue of female subjects and extracted histones from either purified nuclei or intact cells. Direct acid extraction of whole adipocytes was more efficient, yielding about 100 µg of protein with histone content of 60% –70% from 10 mL of fat cells. Differential proteolysis of the protein extracts by trypsin or ArgC-protease followed by nanoLC/MS/MS with alternating CID/ETD peptide sequencing identified 19 histone variants. Four variants were found at the protein level for the first time; particularly HIST2H4B was identified besides the only H4 isoform earlier known to be expressed in humans. Three of the found H2A potentially organize small nucleosomes in transcriptionally active chromatin, while two H2AFY variants inactivate X chromosome in female cells. HIST1H2BA and three of the identified H1 variants had earlier been described only as oocyte or testis specific histones. H2AFX and H2AFY revealed differential and variable N-terminal processing. Out of 78 histone modifications by acetylation/trimethylation, methylation, dimethylation, phosphorylation and ubiquitination, identified from six subjects, 68 were found for the first time. Only 23 of these modifications were detected in two or more subjects, while all the others were individual specific. The direct acid extraction of adipocytes allows for personal epigenetic analyses of human fat tissue, for profiling of histone modifications related to obesity, diabetes and metabolic syndrome, as well as for selection of individual medical treatments

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Energy-efficient RF source power control for opportunistic distributed sensing in wireless passive sensor networks

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    Energy limitation of sensor nodes is the main constraint to be addressed while designing and implementing algorithms for wireless sensor networks (WSN). Recently, to mitigate battery depletion problem and extend network lifetime, wireless passive sensor networks (WPSN) have become a new field of interest. Modulated backscattering is an important communication technique for WPSN to enable unlimited lifetime for sensor nodes. Determination of required number and power level of RF sources for wireless power transfer to sensor nodes is crucial for energy-efficient distributed sensing operation. Furthermore, deployed RF sources can share spectrum opportunistically via incorporation of cognitive radio capability such that desired distributed estimation distortion can be achieved with minimum spectrum utilization by WPSN. Employment of RF sources that radiate power only when spectrum opportunities are available unveils passive opportunistic distributed sensing (PODS). In this paper, first, we model intercepted power by passive sensor from RF sources and reflected power by passive sensor at the sink, and effect of opportunistic access to licensed spectrum bands on instantaneous throughput of sensor nodes. Then, a power level control scheme for RF sources is proposed to achieve desired distortion level with minimum energy consumption while using opportunistic distributed sensing in WPSN. Achieved estimation distortion at sink with respect to number and power level of RF sources, and available spectrum opportunities is investigated, and energy saving provided by proposed power control scheme is assessed for various distortion requirements, channel noise levels, and available spectrum opportunities via simulation experiments. © 2012 IEEE

    RF power source and estimation diversity in distributed sensing with passive wireless communications

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    Sensor nodes constitute a distributed wireless sensing architecture, such that, multiple sensors report their observations. However, sensor networks are comprised of energy-constrained nodes. Therefore, there have been many efforts to devise energy-efficient communication algorithms for sensor networks to achieve reliable and energy-efficient distributed wireless sensing. Recently, to mitigate battery depletion problem and extend network lifetime, wireless passive sensor networks (WPSN) have become a new field of interest. Modulated backscattering is an important communication technique in WPSN to alleviate reaching unlimited lifetime for sensor nodes. In this paper, we theoretically analyze event distortion in WPSN that is employing modulated backscattering for communication. First, we model backscattered power by sensor nodes at RF sources using log-normal channel model. Then, using the backscattered power gain of sensor nodes, the mean square error of estimated signal is analyzed for various number of RF sources and power levels in WPSN. The objective of this work is to reveal the impact of RF source diversity on event estimation distortion in WPSN. © 2011 IEEE

    Reliability and congestion control in cognitive radio sensor networks

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    Communication requirements for cognitive radio sensor networks (CRSN) necessitate addressing the problems posed by dynamic spectrum access (DSA) in an inherently resource-constrained sensor networks regime. In this paper, arising challenges for reliability and congestion control due to incorporation of cognitive radio capability into sensor networks are investigated along with the open research issues. Impact of DSA, i.e., activity of licensed users, intermittent spectrum sensing and spectrum handoff functionalities based on spectrum availability, on the performance of the existing transport protocols are inspected. The objective of this paper is to point out the urgent need for a novel reliability and congestion control mechanism for CRSN. To this end, CRSN challenges for transport layer are revealed and simulation experiments are performed to demonstrate the performance of the existing transport protocols in CRSN. © 2011 Elsevier B.V. All rights reserved

    Cognitive radio sensor networks in industrial applications

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    The need for industrial monitoring and process control has arisen with the demand to overcome production capacity limitations, improve process efficiency, comply with the environmental regulations, predict machine failures, and precaution against natural accidents [14, 18]. Collected information from industrial equipment is used to diagnose efficiency decreases and faults in industrial applications. Therefore, reliable and timely information gathering from industrial equipment is extremely crucial to prevent possible inefficiencies and malfunctions in industrial applications

    Spectrum-aware underwater networks: Cognitive acoustic communications

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    Communication capacity in underwater acoustic networks is severely limited by the uniquely challenging characteristics of underwater acoustic communications (UACs). In this article, dynamic spectrum sharing inspired from cognitive radio (CR) is applied to UAC networks, and spectrum-aware underwater networks (SUNs), i.e., cognitive acoustic communications (CACs), are proposed. First, the problem of spectrum scarcity in SUN is elaborately discussed by investigating the variation in acoustic channel capacity with respect to communication frequency and bandwidth. Then, the analysis of capacity gain via spectrum sharing in SUN is presented. To uncover the capacity gain via CAC, simulation experiments are performed, considering the effects of depth, distance, shipping, waves, spectrum management delay, and spectrum accessibility. The results of simulation experiments revealed a tradeoff between capacity gain and spectrum management delay. Furthermore, the tradeoff for capacity gain and spectrum accessibility period is also discussed. Here, our goal is to envision the potentials of CAC for mitigating spectrum scarcity in UAC. © 2012 IEEE
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